This invention relates to automotive control systems and, more particularly, to condition responsive apparatus for providing an indication of engine malfunction and disabling the engine in the event of such malfunction.
In the past, systems have been devised which shut down engine operation or motor vehicles whenever an adverse operating condition is detected, such as, for example, excessively low engine oil pressure or excessively high engine or transmission temperature. Such systems are particularly well suited for large trucks which typically have very expensive engines. The systems can prevent serious damage to, or total loss of, an engine which would occur if the driver failed to note the presence of the adverse condition from his dashboard instruments, or if the instruments were defective or gave inaccurate readings. Some of these systems suffer from the drawback that the engine is shut down without advance warning, thereby providing a safety hazard to both the driver of the vehicle and to those in close proximity to the vehicle. To overcome this disadvantage, systems have been proposed which permit restarting of the engine and at least brief subsequent operation. While an improvement, this is not entirely satisfactory as the engine has already been shut down. Other systems provide a warning to the driver that the engine will be shut down after some predetermined interval in order to allow the driver time to maneuver the vehicle off the road or to some safe location. This, too, is not entirely satisfactory as the driver might have no safe location to which he can move the vehicle within the allotted time interval. Further systems have been proposed which allow the driver to operate a switch and as long as the switch is operated, the shutdown system is overridden. This, too, is not entirely satisfactory in that the driver must maintain the switch operated and loses a certain amount of dexterity by being forced to operate the switch. In particular, the driver loses the use of one hand. It is, therefore, apparent that a need exists for an improved engine warning and shutdown system.
It is, therefore, an object of the present invention to provide apparatus responsive to adverse engine operating conditions for automatically effecting shutdown of the engine.
It is another object of the present invention to provide such apparatus which gives a warning to the driver and delays the engine shutdown for a predetermined interval.
It is a further object of the present invention to provide such apparatus wherein the driver may override the automatic shutdown operation.
It is still another object of this invention to provide such apparatus wherein the override feature does not require the driver to continuously activate the override function.
It is yet another object of this invention to provide such apparatus which is not sensitive to momentary failures, but rather requires the persistence of an adverse operating condition to effect engine shutdown.